(1) Field of the Invention
The present invention relates to an image display apparatus capable of decoding an encoded bit stream and displaying it.
(2) Description of the Related Art
In IP broadcasting, an image is compressively encoded (i.e., encoded and compressed) according to a syntax specified by MPEG-2, H.264/AVC, etc. into an encoded bit stream, which is transmitted through a network, etc. At that time, if the encoded bit stream has suffered a transmission error, it is usually corrected by, for example, FEC (Forward Error Correction). However, the error may be of the type that cannot be corrected even by such an error correction technique. In that case, the erroneous data (portion) is discarded and hence is not subjected to a decode process. Known techniques for compensating for such data loss include, for example, those disclosed in Japanese Laid-Open Patent Publication Nos. 2005-295054 and 2002-354488.
When a macroblock in an encoded bit stream is corrupted or lost due to an uncorrectable error, the techniques described in these patent publications replace it with a block within a reference image (or the previous frame) indicated by a motion vector for a macroblock adjacent the corrupted or lost macroblock.